Molecular Features and Stages of Pulmonary Fibrosis Driven by Type 2 Inflammation

Systemic sclerosis (SSc) is a progressive, multiorgan disease with limited treatment options. Although a recent proof-of-concept study using romilkimab or SAR156597, a bispecific IL-4/IL-13 antibody, suggests a direct role of these cytokines in the pathophysiology of SSc, their contributions to the balance between inflammation and fibrosis are unclear. Here, we determine the roles of type 2 inflammation in fibrogenesis using FRA2-Tg (Fos-related antigen 2-overexpressing transgenic) mice, which develop spontaneous, age-dependent progressive lung fibrosis. We defined the molecular signatures of inflammation and fibrosis at three key stages in disease progression, corresponding to preonset, inflammatory dominant, and fibrosis dominant biology, and revealed an early increase in cytokine-cytokine receptor interactions and antigen-processing and presentation pathways followed by enhanced Th2- and M2 macrophage-driven type 2 responses. This type 2 inflammation progressed to extensive fibrotic pathology by 14-18 weeks of age, with these gene signatures overlapping significantly with those seen in the lungs of patients with SSc with interstitial lung disease (ILD). These changes were also evident in the histopathology, which showed perivascular and peribronchiolar inflammation with prominent eosinophilia and accumulation of profibrotic M2-like macrophages followed by rapid progression to fibrosis with thickened alveolar walls with multifocal fibrotic bands and signs of interstitial pneumonia. Critically, treatment with a bispecific antibody targeting IL-4 and IL-13 during the inflammatory phase abrogated the Th2 and M2 responses and led to near-complete abrogation of lung fibrosis. These data recapitulate important features of fibrotic progression in the lungs of patients with SSc-ILD and enhance our understanding of the progressive pathobiology of SSc. This study also further establishes FRA2-Tg mice as a valuable tool for testing future therapeutic agents in SSc-ILD.

High-Throughput and Format-Agnostic Mispairing Assay for Multispecific Antibodies Using Intact Mass Spectrometry

Multispecific antibodies have gained significant importance in a broad indication space due to their ability to engage multiple epitopes simultaneously and to thereby overcome therapeutic barriers. With growing therapeutic potential, however, the molecular complexity increases, thus intensifying the demand for innovative protein engineering and analytical strategies. A major challenge for multispecific antibodies is the correct assembly of light and heavy chains. Engineering strategies exist to stabilize the correct pairing, but typically individual engineering campaigns are required to arrive at the anticipated format. Mass spectrometry has proven to be a versatile tool to identify mispaired species. However, due to manual data analysis procedures, mass spectrometry is limited to lower throughputs. To keep pace with increasing sample numbers, we developed a high-throughput-capable mispairing workflow based on intact mass spectrometry with automated data analysis, peak detection, and relative quantification using Genedata Expressionist. This workflow is capable of detecting mispaired species of ∼1000 multispecific antibodies in three weeks and thus is applicable to complex screening campaigns. As a proof of concept, the assay was applied to engineering a trispecific antibody. Strikingly, the new setup has not only proved successful in mispairing analysis but has also revealed its potential to automatically annotate other product-related impurities. Furthermore, we could confirm the assay to be format-agnostic, as shown by analyzing several different multispecific formats in one run. With these comprehensive capabilities, the new automated intact mass workflow can be applied as a universal tool to detect and annotate peaks in a format-agnostic approach and in high-throughput, thus enabling complex discovery campaigns.

A trispecific antibody targeting HER2 and T cells inhibits breast cancer growth via CD4 cells

Effective antitumour immunity depends on the orchestration of potent T cell responses against malignancies¹. Regression of human cancers has been induced by immune checkpoint inhibitors, T cell engagers or chimeric antigen receptor T cell therapies^2-4. Although CD8 T cells function as key effectors of these responses, the role of CD4 T cells beyond their helper function has not been defined. Here we demonstrate that a trispecific antibody to HER2, CD3 and CD28 stimulates regression of breast cancers in a humanized mouse model through a mechanism involving CD4-dependent inhibition of tumour cell cycle progression. Although CD8 T cells directly mediated tumour lysis in vitro, CD4 T cells exerted antiproliferative effects by blocking cancer cell cycle progression at G1/S. Furthermore, when T cell subsets were adoptively transferred into a humanized breast cancer tumour mouse model, CD4 T cells alone inhibited HER2⁺ breast cancer growth in vivo. RNA microarray analysis revealed that CD4 T cells markedly decreased tumour cell cycle progression and proliferation, and also increased pro-inflammatory signalling pathways. Collectively, the trispecific antibody to HER2 induced T cell-dependent tumour regression through direct antitumour and indirect pro-inflammatory/immune effects driven by CD4 T cells.

Impact of lipopolysaccharides on cultivation and recombinant protein expression in human embryonal kidney (HEK-293) cells

The human embryonal kidney 293 cell (HEK-293) is a widely used expression host for transient gene expression. The genes or plasmids used for the transient transfections are usually propagated and extracted from the gram-negative bacterium Escherichia coli, the workhorse for molecular biologists. As a gram-negative bacterium E. coli has an outer membrane (OM) containing lipopolysaccharides (LPS) or endotoxins. LPS are very potent inducers of inflammatory cytokines in the body. In early research phases DNA intended for transient transfections is not routinely checked for LPS-levels. In this study we addressed the question whether LPS has an impact on the cultivation and production of a recombinant antibody. At high concentrations the presence of LPS has a detrimental impact on cell viability and recombinant protein expression. But low LPS concentrations are tolerated and might even enhance protein expression levels.

Pre-clinical development of a novel CD3-CD123 bispecific T-cell engager using cross-over dual-variable domain (CODV) format for acute myeloid leukemia (AML) treatment

Novel therapies are needed for effective treatment of AML. In the relapsed setting, prognosis is very poor despite salvage treatment with chemotherapy. Evidence suggests that leukemic stem cells (LSCs) cause relapse. The cell surface receptor CD123 is highly expressed in blast cells and LSCs from AML patients and is a potential therapeutic target. CD123 cross-over dual-variable domain T-cell engager (CD123-CODV-TCE) is a bispecific antibody with an innovative format. One arm targets the CD3εδ subunit of T-cell co-receptors on the surface of T cells, while the other targets CD123 on malignant cells, leading to cell-specific cytotoxic activity. Here, we describe the preclinical activity of CD123-CODV-TCE. CD123-CODV-TCE effectively binds to human and cynomolgus monkey CD3 and CD123 and is a highly potent T-cell engager. It mediates T-cell activation and T-cell-directed killing of AML cells in vitro. In vivo, CD123-CODV-TCE suppresses AML tumor growth in leukemia xenograft mouse models, where it achieves an effective half-life of 3.2 days, which is a significantly longer half-life compared to other bispecific antibodies with no associated Fc fragment. The in vitro safety profile is as expected for compounds with similar modes of action. These results suggest that CD123-CODV-TCE may be a promising therapy for patients with relapsed/refractory AML.

Abstract 1785: Pre-clinical development of a novel CD3-CD123 bispecific T-cell engager using Cross-Over-Dual-Variable-Domain (CODV) format for the treatment of acute myeloid leukemia (AML)

Acute myeloid leukemia (AML) is characterized by the accumulation of abnormal blast cells in the bone marrow and blood. While high intensity chemotherapy and allogeneic stem cell transplantation cure a subset of patients with AML, many patients are ineligible or do not respond sufficiently to these therapies. One potential reason for treatment failure in a particular patient may be the inability to reach and eliminate residual leukemic stem cells (LSCs) located in the bone marrow. T-cell mediated cytotoxicity, targeting LSCs with high expression of certain leukemic antigens, represents an attractive therapeutic strategy for relapsed and refractory AML. In this study, the proprietary Cross-Over-Dual-Variable-Domain (CODV) format was applied to a fully humanized IgG1 backbone with reduced Fc functionality, resulting in a bispecific T-cell engager (TCE), CD123-CODV-TCE, that binds to both CD3 on T cells and CD123 (α-chain of the interleukin-3 receptor) on AML blasts and LSCs. CD123-CODV-TCE displayed high affinity for human CD123 and medium affinity for human CD3 proteins. As expected, CD123-CODV-TCE activated CD4-positive and CD8-positive T cells only in the presence of cells expressing the CD123 target, such as THP1 (an AML tumor cell line), and induced killing of these cells with an EC50 in a picomolar range. Potential cytotoxic activity of CD123-CODV-TCE was also evaluated on CD123-expressing normal blood cells such as plasmacytoid dendritic cells (pDC) and monocytes. CD123-CODV-TCE was shown to deplete pDC and monocyte from human Healthy Donor (HD) Peripheral Blood Mononuclear Cells (PBMC) with an EC50 in the picomolar range. This efficacy correlated with the release of numerous cytokines, thus highlighting the potential risk of cytokine release syndrome as described for other TCE's. In an in vivo disseminated AML model using CD123+ Molm13-luc human AML cell line, treatment of the mice with CD123-CODV-TCE suppressed AML tumor growth in the bone marrow compartment following co-injection of primary human T cells. In this murine pre-clinical model, CD123-CODV-TCE displayed favorable pharmacokinetic properties with a terminal half-life of 3 days. To investigate CD123-CODV-TCE activity on myeloid blast cells and LSC, in vivo efficacy studies were performed in NSG mice injected with primary human AML cells obtained from patients. In this model, CD123-CODV-TCE induced the killing of primary AML cells by activating human autologous T cells. Taken together, these results indicate that CD123-CODV-TCE can potently and specifically kill CD123+ leukemic cancer cells in vitro and in vivo. CD123-CODV-TCE therefore represents a potential candidate for future clinical development in relapsed and refractory AML.

Citation Format: Helene Bonnevaux, Stephane Guerif, Jana Albrecht, Erwan Jouannot, Laurent Bassinet, Agnès Vergezac, Christian Beil, Christian Lange, Wulf Dirk Leuschner, Anne Caron, Celine Amara, Cedric Barriere, Justine Siavellis, Valerie Bardet, Ernesto Luna, Donald Drake, Ercole Rao, Corina Oprea, Peter Wonerow, Chantal Carrez, Veronique Blanc, Karl Hsu, Dmitri Wiederschain, Paula G. Fraenkel. Pre-clinical development of a novel CD3-CD123 bispecific T-cell engager using Cross-Over-Dual-Variable-Domain (CODV) format for the treatment of acute myeloid leukemia (AML) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1785.

Trispecific broadly neutralizing HIV antibodies mediate potent SHIV protection in macaques

The development of an effective AIDS vaccine has been challenging because of viral genetic diversity and the difficulty of generating broadly neutralizing antibodies (bnAbs). We engineered trispecific antibodies (Abs) that allow a single molecule to interact with three independent HIV-1 envelope determinants: the CD4 binding site, the membrane-proximal external region (MPER), and the V1V2 glycan site. Trispecific Abs exhibited higher potency and breadth than any previously described single bnAb, showed pharmacokinetics similar to those of human bnAbs, and conferred complete immunity against a mixture of simian-human immunodeficiency viruses (SHIVs) in nonhuman primates, in contrast to single bnAbs. Trispecific Abs thus constitute a platform to engage multiple therapeutic targets through a single protein, and they may be applicable for treatment of diverse diseases, including infections, cancer, and autoimmunity.

CODV-Ig, a universal bispecific tetravalent and multifunctional immunoglobulin format for medical applications

Bispecific immunoglobulins (Igs) typically contain at least two distinct variable domains (Fv) that bind to two different target proteins. They are conceived to facilitate clinical development of biotherapeutic agents for diseases where improved clinical outcome is obtained or expected by combination therapy compared to treatment by single agents. Almost all existing formats are linear in their concept and differ widely in drug-like and manufacture-related properties. To overcome their major limitations, we designed cross-over dual variable Ig-like proteins (CODV-Ig). Their design is akin to the design of circularly closed repeat architectures. Indeed, initial results showed that the traditional approach of utilizing (G4S)x linkers for biotherapeutics design does not identify functional CODV-Igs. Therefore, we applied an unprecedented molecular modeling strategy for linker design that consistently results in CODV-Igs with excellent biochemical and biophysical properties. CODV architecture results in a circular self-contained structure functioning as a self-supporting truss that maintains the parental antibody affinities for both antigens without positional effects. The format is universally suitable for therapeutic applications targeting both circulating and membrane-localized proteins. Due to the full functionality of the Fc domains, serum half-life extension as well as antibody- or complement-dependent cytotoxicity may support biological efficiency of CODV-Igs. We show that judicious choice in combination of epitopes and paratope orientations of bispecific biotherapeutics is anticipated to be critical for clinical outcome. Uniting the major advantages of alternative bispecific biotherapeutics, CODV-Igs are applicable in a wide range of disease areas for fast-track multi-parametric drug optimization.

Human retroviral gag- and gag-pol-like proteins interact with the transforming growth factor-beta receptor activin receptor-like kinase 1

Mutations in activin receptor-like kinase 1 (ALK1), a transforming growth factor (TGF)-beta type I receptor, lead to the vascular disorder hereditary hemorrhagic telangiectasia caused by abnormal vascular remodeling. The underlying molecular cause of this disease is not well understood. Identifying binding partners for ALK1 will help to understand its cellular function. Using the two-hybrid system, we identified an ALK1-binding protein encoded by an ancient retroviral/retrotransposon element integrated as a single copy gene known as PEG10 on human chromosome 7q21. PEG10 contains two overlapping reading frames from which two proteins, PEG10-RF1 and PEG10-RF1/2, are translated by a typical retroviral -1 ribosomal frameshift mechanism. Reverse transcription-PCR and Northern blot analysis showed a broad range of PEG10 expression in different tissues and cell types, i.e. human placenta, brain, kidney, endothelial cells, lymphoblasts, and HepG2 and HEK293 cells. However, endogenous PEG10-RF1 and PEG10-RF1/2 proteins were only detected in HepG2 and HEK293 cells. PEG10-RF1, which is the major PEG10 protein product, represents a gag-like protein, and PEG10-RF1/2 represents a gag-pol-like protein. PEG10-RF1 also interacts with different members of TGF-beta superfamily type I and II receptors. PEG10-RF1 binding to ALK1 is mediated by a 200-amino acid domain with no recognized motif. PEG10-RF1 inhibits ALK1 as well as ALK5 signaling. Co-expression of ALK1 and PEG10-RF1 in different cell types induced morphological changes reminiscent of neuronal cells or sprouting cells. This is the first report of a human retroviral-like protein interacting with members of the TGF-beta receptor family.

Arztbriefe neurologischer Kliniken in der Sicht niedergelassener Neurologen und Nerven�rzte

Eight discharge reports involving five diagnoses (anterior territory ischemic stroke, epilepsy, Parkinson's syndrome, multiple sclerosis, polyneuropathy) from five neurological departments were peer-reviewed by five neurologists working in out-patient (private) practice. The review considered the diagnosis, case history, clinical status, laboratory investigation, differential diagnosis and treatment. Criticism mainly involved the quality of the clinical assessment, lack of clinical status at discharge, narrow or incomplete differential diagnosis and the quality of the neurophysiological investigations for epilepsy and polyneuropathy. Improvement potential was seen for the speed of reporting, better comprehensibility, omission of irrelevant information, greater participation of experienced neurologists in report writing, and standardization.

Effect of nimodipine on glucose metabolism in the course of ischemic stroke

We investigated the effect of the calcium channel-blocking agent nimodipine on regional cerebral metabolic rate of glucose in acute ischemic middle cerebral artery infarction diagnosed clinically and by computed tomography. Twenty-seven patients entered the study within 48 hours after onset of symptoms and randomly received either nimodipine (2 mg/hr constant intravenous infusion for 5 days, 120 mg/day orally for another 16 days) or placebo. Four of the 27 patients died within the first 3 weeks and could not be evaluated. Of the remaining 23 patients, 11 were assigned to the nimodipine group and 12 to a control group. We analyzed data from positron emission tomography, performed twice before and after completion of therapy, and clinical data from the treatment period and the next 6 months based on the Mathew Score for early assessment and the Barthel Index for late assessment. During the post-treatment period, two patients from the nimodipine group and three from the control group died. The evaluated patients were comparable for age and sex distribution, initial clinical deficit, and infarct size and localization. We found significant metabolic changes between both treatment groups for contralateral infarct mirror region, ipsilateral and contralateral cerebral gray matter, and contralateral and ipsilateral cerebellar hemispheres (side x region x treatment interaction p less than 0.025). The nimodipine group had bilaterally increased regional cerebral metabolic rate of glucose of morphologically intact cerebral (14.6% and 17.1%, respectively) and cerebellar structures (6.9% and 10%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

[Diagnosis and prognosis of acute cerebellar infarcts. A retrospective study]

37 patients with acute cerebellar infarction were analysed retrospectively. Diagnosis of cerebellar infarction cannot be made by clinical symptoms alone rather together with CT and MRT displaying the localisation and size of the lesion. Evoked potentials do predict clinical outcome more accurately than EEG or doppler sonography do.

Quantitation of lymphocyte subsets in cerebrospinal fluid and blood during the clinical course of aseptic and bacterial meningitis

Mononuclear cell subsets in cerebrospinal fluid (CSF) and peripheral blood (PB) were monitored during the clinical course in 23 patients with acute meningitis using 6 monoclonal antibodies. Significant differences between aseptic and bacterial meningitis mainly consisted of a higher percentage of OKT4-positive cells in PB in the acute phase of bacterial meningitis. Significant differences between CSF and PB are found in the amount of most cell subtypes at all times except the acute phase of bacterial meningitis. The OKT4/OKT8 ratio was always significantly higher in CSF and correlated with the acuity of inflammation in bacterial meningitis.

Generalized decrease in brain glucose metabolism during fasting in humans studied by PET

In prolonged fasting, the brain derives a large portion of its oxidative energy from the ketone bodies, beta-hydroxybutyrate and acetoacetate, thereby reducing whole body glucose consumption. Energy substrate utilization differs regionally in the brain of fasting rat, but comparable information has hitherto been unavailable in humans. We used positron emission tomography (PET) to study regional brain glucose and oxygen metabolism, blood flow, and blood volume in four obese subjects before and after a 3-wk total fast. Whole brain glucose utilization fell to 54% of control (postabsorptive) values (P less than 0.002). The whole brain rate constant for glucose tracer phosphorylation fell to 51% of control values (P less than 0.002). Both parameters decreased uniformly throughout the brain. The 2-fluoro-2-deoxy-D-glucose lumped constant decreased from a control value of 0.57 to 0.43 (P less than 0.01). Regional blood-brain barrier transfer coefficients for glucose tracer, regional oxygen utilization, blood flow, and blood volume were unchanged.

Anatomical-functional correlation using an adjustable MRI-based region of interest atlas with positron emission tomography

A procedure is described for combining anatomical information from magnetic resonance imaging (MRI) or computerized tomography (CT) and functional information from positron emission tomography (PET) in a rapid fashion. MRI data are combined with a procedure for the definition, storage, and recall of anatomically based regions of interest. An atlas of standard regions of interest, defined for a set of 18 parallel planes spaced at 6-mm intervals, provides an initial region of interest template for each patient slice. Global adjustments to scale, orientation, and position are applied to obtain an initial match. Individual regions of interest may then be moved, deleted, or redrawn as needed. The ability to store region of interest templates ensures reproducibility of analysis over long periods and introduces a standardization of analysis technique. In 25 brain structures, the mean coefficient of variation in cerebral glucose utilization rate (CMRGlc) measurements among five neuroanatomically trained observers was reduced from 8.1% for manual region of interest definition to 4.0% using the template approach with MRI. Template analysis for space-occupying lesions such as tumors or infarcts is illustrated with PET data from a stroke study, emphasizing the facility for rapid, reproducible analysis of multifunctional studies. MRI-PET matching for a structurally intact caudate nucleus having reduced CMRGlc in Huntington's disease emphasizes the accuracy of anatomical localization required to quantify small structures.

Comparative analysis of regional brain blood flow and glucose metabolism in focal cerebrovascular disease measured by dynamic positron emission tomography of fluorine-18-labelled tracers

Regional cerebral blood flow (rCBF) and glucose metabolism (rCMRglc) were measured in 44 patients with various kinds of focal vascular brain lesions, using multislice positron emission tomography (PET). Haemodynamic data were obtained by a recently developed, non-invasive clearance method utilizing (18F)-methyl fluoride as a diffusible, gaseous indicator. Shortly after completion of each flow study, rCMRglc was dynamically determined by standard procedures using 2(18F)-fluorodeoxyglucose. While blood flow and glucose consumption in the structurally damaged area were often uncoupled during the acute phase, metabolism-to-flow ratios were markedly less scattered at later stages of cerebrovascular disease. Individual maximum-likelihood cluster analysis of brain regions revealed remarkable similarity between deactivation patterns of rCBF and rCMRglc, with Tanimoto coefficients averaging 0.56. This similarity was inversely related to the residual rCMRglc of the lesion. These findings are in line with results obtained by PET of other tracers, suggesting that the pair of methods provides valuable and somewhat complementary information on brain function and mechanisms of cerebral vascular disease.

Regional cerebral glucose metabolism in anorexia nervosa measured by positron emission tomography

Regional cerebral glucose metabolism was measured in five female anorectic patients, during the anorectic state and after weight gain, using the fluorodeoxyglucose method and positron emission tomography. In addition, these results were compared with those of 15 young male normals. During the anorectic state, significant caudate hypermetabolism was found bilaterally, unlike the finding in repeat measurements or in male normals. In some other brain structures (temporal cortex, lentiform nucleus, thalamus, and brainstem), significant hypermetabolism was also found during the anorectic state, but these results were not concordant for both sides and in both comparisons. There was no difference between patients after improvement and young male normals.

[Cerebral glucose metabolism in presenile dementia of the Alzheimer type--follow-up of therapy with muscarinergic choline agonists]

In 8 patients who had clinically diagnosed presenile dementia (Alzheimer's disease) the cerebral glucose metabolism was repeatedly determined via FDG-PET under therapy with a muscarinergic choline agonist. The pattern of glucose metabolism disturbance characteristic of Alzheimer's disease, which had been determined previously by examining the metabolism, was confirmed. Whereas the total cortical glucose metabolism was significantly reduced, the regions of the parietal and the adjacent regions of the temporal and occipital association cortex were preferably affected. The primary somatosensory and visual cortex were largely excepted from the reduction in metabolism or showed slightly enhanced metabolic rates, as for example the cerebellum. The disturbance was not equilaterally pronounced and correlated with the neuropsychological deficiency. Despite biochemically "on target" therapy the glucose metabolism decreased progressively (mean value with large interindividual and intraindividual variations. No relationship between the degree of reduced metabolism and the clinical pattern was seen. Rather, it appears that the clinical pattern is much more strongly influenced by mutual adjustment of metabolic differences in various areas of the brain. Results obtained by the authors are communicated besides a review of update knowledge and interpretation of pathophysiological and biochemical linkups in Alzheimer's disease, taking into consideration the glucose metabolism studies published in the literature.

Positron emission tomography in depression research: principles--results--perspectives

At present, PET is the only technology affording the quantitative, three-dimensional imaging of various aspects of brain function. In the few PET studies of mood disorders performed so far, usually cerebral glucose metabolism was investigated by the fluorodeoxyglucose method. Its largest individual diagnostic potential was demonstrated in certain forms of organic depression, while metabolic abnormalities in major unipolar and bipolar depression were more subtle--albeit significantly different. Other PET tracers for investigation of transmitter systems are available, but have not been systematically applied in depression research.